New insights into the relationship of neurogenesis and affect: tickling induces hippocampal cell proliferation in rats emitting appetitive 50-kHz ultrasonic vocalizations.
It seems that tickling causes nerogenesis in rats that like to be tickled, but not rats that don't. For the uninformed: yes, rats are ticklish, and it appears that they laugh--at 50 hHz.
Laugh yourself smart... what a concept.
Edited by LabRat84, 27 April 2010 - 07:23 AM.